The present invention relates generally to a magnetic component having at least one conductive winding and more specifically to a magnetic component having a bobbin structure for winding a conductive coil. More particularly the present invention relates to a bobbin structure having a molded bobbin body including a first conductive winding embedded therein.
Magnetic components utilizing a bobbin structure for positioning a conductive winding are known in the prior art. These components, including certain transformers and inductors, are commonly used in power supply circuits, such as those found in lighting assemblies and other electronic devices. Such components are often referred to as bobbin-wound components.
Generally, in a bobbin-wound component, at least one coil, or winding, of conductive material is wound around a bobbin structure. Typically, the bobbin structure includes a hollow cavity for inserting a ferrite core. The winding is placed around the exterior of the bobbin structure surrounding the hollow cavity. During use, current is passed through at least one conductive coil, and a magnetic field is generated by the flow of electrons through the coil. The magnetic field is guided and concentrated by the ferrite core positioned in the hollow cavity. Each conductive coil in a bobbin-wound component may include of one or more turns around the bobbin structure. The performance of the component is determined in part by the number of turns of each conductive coil around the bobbin structure and by the position of each coil on the bobbin structure.
A common prior art bobbin-wound component configuration includes a bobbin structure having a hollow interior cavity, a first conductive coil wound onto the bobbin structure and a second conductive coil wound onto the same bobbin structure. In many applications, it is desirable for the first coil to include a conductive wire wound less than one complete revolution around the bobbin structure. A coil forming less than one complete revolution around the bobbin structure is referred to as a single-turn winding. In such a component, the placement of the single-turn winding must be precise for the component to function as intended. Even a minor deviation from the proper single-turn winding placement can result in component failure.
For example, in the prior art, a single-turn winding is typically positioned on the exterior of the bobbin structure. As such, the single-turn winding may shift along the exterior of the bobbin structure during use, resulting in component malfunction or failure. The prior art also teaches a magnetic component having an individual insulated single-turn winding that can be inserted into a bobbin structure. In the prior art, the bobbin structure and the insertable single-turn winding are separate pieces, and the single-turn winding may shift relative to the bobbin structure during use, causing undesired performance fluctuations or component failure. Also, the two-piece design of the prior art adds complexity to the design of the bobbin structure, requiring multiple components.
Other conventional bobbin-wound components generally include multiple windings positioned on one bobbin structure. The windings include a conductive wire coated with electrically insulating enamel. The coated wire is wound around the bobbin structure to form each winding. The enamel on the wire is included to prevent electrical contact between each winding. However, conventional bobbin-wound components allow partially exposed regions of the windings to occasionally form an undesired electrical contact between the windings. Electrical contact between windings can cause component failure.
The conventional practice for producing bobbin-wound components includes positioning the single-turn winding onto the bobbin structure using a winding machine. The rate of production of bobbin-wound components having a single-turn winding is often limited by the time required for the winding machine to properly position the single-turn winding onto the bobbin structure. Precise positioning of the single-turn winding generally increases the overall component winding time and, thus, limits the overall rate of bobbin-wound component production.
Accordingly, there is a need in the art for providing a magnetic component having a bobbin structure with an integrated winding for reducing component production time, providing electrical insulation between windings and reducing component failure due to misplaced single-turn windings.